Performance evaluation of potent phosphate solubilizing bacteria in potato rhizosphere
- 768 Downloads
Three phosphate solubilizing bacterial isolates identified as Pantoea agglomerans strain P5, Microbacterium laevaniformans strain P7 and Pseudomonas putida strain P13 were assessed for mutual relationships among them, competitiveness with soil microorganisms and associations with plant root using luxAB reporter genes for follow-up studies. Synergism between either P. agglomerans or M. laevaniformans, as acid-producing bacteria, and P. putida, as a strong phosphatase producer, was consistently observed both in liquid culture medium and in root rhizosphere. All laboratory, greenhouse and field experiments proved that these three isolates compete well with naturally occurring soil microorganisms. Consistently, the combinations of either P. agglomerans or M. laevaniformans strains with Pseudomonas putida led to higher biomass and potato tuber in greenhouse and in field trials. It is conceivable that combinations of an acid- and a phosphatase-producing bacterium would allow simultaneous utilization of both inorganic and organic phosphorus compounds preserving the soil structure.
KeywordsPhosphate solubilization Pantoea agglomerans Microbacterium laevaniformans and Pseudomonas putida Biofertilizer Potato
This research was partially supported by a grant from National Research Council of I.R. Iran. We would like to thank Prof. Hani Antoun for his critical revision of this manuscript.
- Buell CR, Anderson AJ (1992) Genetic analysis of the aggA locus involved in agglutination and adherence of Pseudomonas putida a beneficial fluorescent pseudomonad. Mol Plant Microbe Interact 5:154–162Google Scholar
- Chabot R, Antoun H, Kloepper JW, Beauchamp CJ (1996) Root colonization of maize and lettuce by bioluminescent Rhizobium leguminosarum biovar phaseoli. Appl Environ Microbiol 62:2767–2772Google Scholar
- de Weger LA, Bloemberg GV, van Wezel T, van Raamsdonk M, Glandorf DC, van Vuurde J, Jann K, Lugtenberg BJ (1996) A novel cell surface polysaccharide in Pseudomonas putida WCS358 which shares characteristics with Escherichia coli K antigens is not involved in root colonization. J Bacteriol 178:1955–1961Google Scholar
- Fisk CH, Sabbarow Y (1925) A colorimetric determination of phosphate. J Biol Chem 66:375–400Google Scholar
- Kuiper I, Kravchenko LV, Bloemberg GV, Lugtenberg BJ (2002) Pseudomonas putida strain PCL1444 selected for efficient root colonization and naphthalene degradation effectively utilizes root exudates components. Mol Plant Microbe Interact 15:734–741. doi: 10.1094/MPMI.2002.15.7.734 CrossRefGoogle Scholar